The main purpose of this study is to determine if high doses of radiation using proton beam can be given safely with low and acceptable side effects. We will also gather information to determine the ability of proton beam to destroy cancer cells in the liver. There are two types of external radiation treatments (proton beam and photon beam). Proton beam radiation is a very accurate kind of treatment that has been shown to affect less normal tissue than a regular radiation beam. The accuracy allows us to more safely increase the amount of radiation delivered to eliminate cancer and may potentially reduce the side effects normally experienced with standard radiation therapy.

• Participants will receive treatment as an outpatient at the Northeast Proton Treatment Center located at the Massachusetts General Hospital.
• Since we are looking for the highest dose of proton beam radiation that can be given to people safely, not everyone who participates in this study will be receiving the same amount of radiation. Small groups of people will be enrolled and given a certain dose of radiation. If they tolerate it well, the next small group of people enrolled will receive a higher dose. This will continue until we find the highest dose that can be given without causing serious or unmanageable side effects.
• Radiation treatment to the liver will be given once a day, 5 days a week (Monday-Friday), for 3 weeks. Each treatment takes about 10-20 minutes.
• A physical examination, medical history, and blood tests will be taken once a week for 3 weeks during radiation therapy. Follow-up visits will occur every 3 months for 2 years, and every 6 months thereafter for 3 years, and then annually thereafter.

Inclusion Criteria:

• Biopsy proven unresectable or locally recurrent hepatocellular cancer, cholangiocarcinoma, or hepatic metastases.
• Primary lesion size of 6cm or less in greatest diameter
• Single or multinodular tumors (up to 3)
• 18 years of age or older
• No evidence of extrahepatic tumor
• Karnofsky performance status of 70-100
• If patient has underlying cirrhosis, only Child's classification Group A or Group B
• Adequate renal function
• Expected survival of greater than three months

Exclusion Criteria:

• Pregnant or lactating women
• Evidence of non-hepatic metastatic disease
• Local conditions or systemic illnesses which would reduce the local tolerance to radiation treatment, such as serious local injuries, active collagen vascular disease, etc.
• Prior radiation treatment to affected region
• Serious psychiatric illness which would limit compliance with treatment